It is the purpose of this article to permit local governmental units to make the most efficient use of their power and authority by enabling them to cooperate with each other on a basis of mutual advantage and to consolidate functions and thereby to provide services and facilities in a manner and pursuant to forms of governmental organization which will result in economies in the operation of local government and which will accord best with the geographic, economic, population and other factors influencing the needs and development of local governmental services and facilities, and thus promote the public health, safety and welfare.